The present invention relates to techniques used in the construction industry for installing insulated electrical conductors inside hollow conduits. In particular, the invention relates to lubricant compositions and methods of use for lubricating the insulated flexible electrical conductors to facilitate installation inside hollow conduits.
It is well known that building and fire codes require that insulated flexible electrical conductors be housed inside rigid hollow conduits so as to protect the conductors from excessive flexing and fatigue over time. The hollow conduits also serve to protect the insulated flexible conductors from exposure to the immediate environment surrounding the hollow conduit.
A common problem associated with installing the insulated conductor inside the conduit is the impediment to installation created by the friction between the inner wall of the conduit and the insulation of the conductor. The friction both slows down the installation process and may even prohibit conductor installation beyond a certain limit.
Previously, liquid, paste, or gel lubricants have been applied to the outer surfaces of the electrical insulation prior to insertion into the hollow conduit in order to reduce the friction that is encountered. Generally, the lubricants are of a petroleum base and are characterized by certain undesirable aspects such as being messy to apply and creating a time consuming and wasteful clean up process. In addition, the waste in time for cleaning up is accompanied by a concomitant waste in lubricant material that results from using liquid lubricants. In order to assure a constant presence of a lubrication layer between the outer surface of the electrical insulation and the inner wall of the hollow conduit, the lubricant composition must be applied either continuously or periodically to the insulation prior to its advancement and entrance into the hollow conduit. Thus, both time and attention to lubricating the insulation must be expended as this technique is employed.